JavaScript Arrays & Functions Quiz

Arrays

1 What will be the output of the following code?

let sum = 0;
for (let i = 1; i <= 5; i++) {
    sum += i;
}
console.log(sum);

A) 10 B) 15 C) 5 D) 20

Loops

2 What is the output of the following while loop?

let i = 0;
while (i < 3) {
    console.log(i);
    i++;
}

A) 0 1 2 B) 0 1 C) 1 2 3 D) 1 2

Loops

3 What will the output of the following code be?

let i = 0;
for (i = 0; i < 3; i++) {
    console.log(i);
    while (i == 1) {
        console.log("Inside while loop");
        break;
    }
}

A) 0 1 Inside while loop 2 B) 0 1 2 Inside while loop C) 0 1 2 D) 0 Inside while loop 2

Methods

4 What is the output of the following code?

let str = "apple,banana,cherry";
let arr = str.split(",");
console.log(arr);

A) ["apple", "banana", "cherry"] B) ["apple banana cherry"] C) ["apple,banana,cherry"] D) ["apple", "banana", "cherry", ""]

Methods

5 Which of the following will join the array ["apple", "banana", "cherry"] into a string "apple-banana-cherry"?

A) arr.join(" ") B) arr.join("-") C) arr.split("-") D) arr.join(",")

Arrays

6 What will be the result of the following code?

let arr = [1, 2, 3, 4, 5];
arr[3] = 10;
console.log(arr);

A) [1, 2, 3, 10, 5] B) [1, 2, 3, 4, 5, 10] C) [1, 2, 3, 4, 5, 6] D) [10, 2, 3, 4, 5]

Functions

7 Which of the following correctly defines a function named "greet" that logs "Hello, World!"?

A) function greet() { console.log("Hello, World!"); } B) function greet() = { console.log("Hello, World!"); } C) function greet { console.log("Hello, World!"); } D) function greet(): { console.log("Hello, World!"); }

Functions

8 Which of the following is the correct way to call a function named "initialize()" when the page loads?

A) <body onload="initialize()"> B) window.onload = initialize(); C) initialize() D) <body onload="initialize()">

Loops

9 The following code produces an infinite loop. What is wrong with it?

let i = 0;
for (i = 0; i < 10;) {
    console.log(i);
}

A) The loop condition is incorrect. B) The increment part is missing in the loop. C) The variable i is not defined correctly. D) The loop needs a break statement.

Methods

10 The following code doesn't produce the correct result. What is wrong?

let text = "apple-banana-cherry";
let result = text.split("-");
console.log(result);

A) The separator is incorrect; it should be ",". B) split() method is used incorrectly. C) The separator should be a space " ". D) The split() method will not work with dashes.

JavaScript Quiz: Loops and Functions

1 What will be the output of the following code?

2 What is the output of the following while loop?

3 What will the output of the following code be?

4 What is the output of the following code?

5 Which of the following will join the array ["apple", "banana", "cherry"] into a string "apple-banana-cherry"?

6 What will be the result of the following code?

7 Which of the following correctly defines a function named "greet" that logs "Hello, World!"?

8 Which of the following is the correct way to call a function named "initialize()" when the page loads?

9 The following code produces an infinite loop. What is wrong with it?

10 The following code doesn't produce the correct result. What is wrong?

Answer Key